Biology 111 Chapter 25 Flowering Plants: Nutrition and Transport

Plant Nutrition

The study of how a plant gains and uses mineral nutrients from the soil.

Mineral

An inorganic substance, usually containing two or more elements.

Why do Plants need mineral from the soil?

Nitrogen is a major component of nucleic acids and proteins, magnesium a component of chlorophyll, and iron the building block of cytochrome molecules. All of these absorbed from the soil.

Essential Macronutrients For Plants

Carbon, Hydrogen, Oxygen, Phosphorous, Potassium, Nitrogen, Sulfur, Calcium, and Magnesium.

Micronutrients

Iron, Boron, Manganese, Copper, Zinc, Chlorine, and Molybdenum

Hydroponics

Method devised by Wilhelm Knop for growing plants by suspending them with their roots in a nutrient solution.

Soil

mixture of mineral particles, decaying organic material , living organisms, air, and water, which together support the growth of plants. Created by the breaking down of rock.

Humus

causes the soil to have a loose, crumbly texture that allows water to soak in without doing away with air spaces. Decreases the chances of runoff, swells when it absorbs water and shrinks when it dries, helps aerate soil, and plants do well in soils that contain 10-20% humus. Humus is acidic therefore is retains positively charged material.

What is the organic matter in humus broken down by?

Bacteria and fungi

Sand Particles

Largest particles (0.05-2.0mm in diameter)

Silt Particles

Intermediate size particles (0.002-0.05mm)

Clay Particles

Smallest particles (<0.002).

Loam Soil

Soil ideal for agriculture that consists of a roughly equal mixture of clay, sand, and silt.

Cation Exchange

Mechanism by which plant roots obtain minerals by exchanging hydrogen ions for other positively charged mineral ions. Important for soil to have a balance of clay and humus that cause this.

Soil Profile

a vertical section from the ground surface to the unaltered rock below.

Soil Horizon

Major layer of soil visible in vertical profile; for example, topsoil is the A horizon.

Soil Erosion

Movement of topsoil to a new location due to the action of wind or running water.

Coastal Erosion

refers to the dramatic result of a hurricane or storm surges that reshape a coastal landscape. Trees and their roots can prevent.

Plasma-membrane Pump

Also called a proton pump, hydrolyzes ATP and uses the energy released to transport H+ ions. Result is an electrochemical gradient that drives positively charged ions such as Potassium through a protein channel into the cell.

Root Nodules

Involved in a mutualistic relationship with bacteria. Assist in obtaining mineral nutrients.

Bacterial Nitrogen Fixation

responsible for most of the conversion of nitrogen from the air into ammonium.

Rhizobia

general term used for bacteria that undergo nitrogen fixation in a symbiotic relationship with plants of the legume family. Requires an anaerobic environment. Live in root nodules.

Mycorrhizae

Mutualistic relationship between fungal hyphae and roots of vascular plants.

Tracheids

tapered at both ends. the ends overlap with those of adjacent tracheids, and pits allow water to pass from one tracheid to another.

Vessel Elements

long tubular cells open at both ends, arranged end to end forming vessels that function like water pipes

Nuclei

What do sieve-tube members lack?

Companion Cells

Have nuclei, and provide proteins to sieve-tube members

Water Potential

Potential energy of water; a measure of the capability to release or take up water relative to another substance.

Root Pressure

Osmotic pressure caused by active movement of minerals into root cells; elevates water in xylem for a short distance.

Guttation

Liberation of water droplets from the edges and tips of leaves, resulting from root pressure.

Cohesion-tension Model

Explanation for upward transport of water in xylem based upon transpiration-created tension and the cohesive properties of water molecules.

Transpiration

Plant's loss of water to the atmosphere, mainly through evaporation at leaf stomata.

Cohesion

Tendency of water molecules to cling to each other or to form hydrogen bonds with other water molecules.

Adhesion

Tendency of water molecules to cling to each other or to form hydrogen bonds with other water molecules.

Water Column

In plants, water molecules joined together in xylem from the leaves to the roots.

Tension

Evaporation of water at the leaves exert

Closes

When a plant is under water stress the stomata

Carbon Dioxide

When the stomata is closed what cannot enter the leaves and allow for photosynthesis to occur correctly?

Stoma

small pore in the leaf epidermis

Guard Cells

border the stoma

Sunlight

detected by flavin pigment and activates proton pump

Phloem

specific tissue that transfers the products of photosynthesis

Source

In the pressure-flow model of phloem transport, the location (leaves) of sugar production. Sugar will flow from the leaves to the sink.

Sink

In the pressure-flow model of phloem transport, the location (roots) from which sugar is constantly being removed. Sugar will flow to the roots from the source.

Pressure-floe Model

Explanation for phloem transport; osmotic pressure following active transport of sugar into phloem produces a flow of sap from a source to a sink.